﻿using System.Collections.Generic;
using System.Text.RegularExpressions;

/********************************************************************************

Copyright (c) 2013 Scott Kirkland

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

********************************************************************************/

namespace Fhwk.Core.Utils.Helpers
{
    public static class Inflector
    {
        #region Default Rules

        static Inflector()
        {
            AddPlural("$", "s");
            AddPlural("s$", "s");
            AddPlural("(ax|test)is$", "$1es");
            AddPlural("(octop|vir|alumn|fung)us$", "$1i");
            AddPlural("(alias|status)$", "$1es");
            AddPlural("(bu)s$", "$1ses");
            AddPlural("(buffal|tomat|volcan)o$", "$1oes");
            AddPlural("([ti])um$", "$1a");
            AddPlural("sis$", "ses");
            AddPlural("(?:([^f])fe|([lr])f)$", "$1$2ves");
            AddPlural("(hive)$", "$1s");
            AddPlural("([^aeiouy]|qu)y$", "$1ies");
            AddPlural("(x|ch|ss|sh)$", "$1es");
            AddPlural("(matr|vert|ind)ix|ex$", "$1ices");
            AddPlural("([m|l])ouse$", "$1ice");
            AddPlural("^(ox)$", "$1en");
            AddPlural("(quiz)$", "$1zes");

            AddSingular("s$", "");
            AddSingular("(n)ews$", "$1ews");
            AddSingular("([ti])a$", "$1um");
            AddSingular("((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$", "$1$2sis");
            AddSingular("(^analy)ses$", "$1sis");
            AddSingular("([^f])ves$", "$1fe");
            AddSingular("(hive)s$", "$1");
            AddSingular("(tive)s$", "$1");
            AddSingular("([lr])ves$", "$1f");
            AddSingular("([^aeiouy]|qu)ies$", "$1y");
            AddSingular("(s)eries$", "$1eries");
            AddSingular("(m)ovies$", "$1ovie");
            AddSingular("(x|ch|ss|sh)es$", "$1");
            AddSingular("([m|l])ice$", "$1ouse");
            AddSingular("(bus)es$", "$1");
            AddSingular("(o)es$", "$1");
            AddSingular("(shoe)s$", "$1");
            AddSingular("(cris|ax|test)es$", "$1is");
            AddSingular("(octop|vir|alumn|fung)i$", "$1us");
            AddSingular("(alias|status)es$", "$1");
            AddSingular("^(ox)en", "$1");
            AddSingular("(vert|ind)ices$", "$1ex");
            AddSingular("(matr)ices$", "$1ix");
            AddSingular("(quiz)zes$", "$1");

            AddIrregular("person", "people");
            AddIrregular("man", "men");
            AddIrregular("child", "children");
            AddIrregular("sex", "sexes");
            AddIrregular("move", "moves");
            AddIrregular("goose", "geese");
            AddIrregular("alumna", "alumnae");

            AddUncountable("equipment");
            AddUncountable("information");
            AddUncountable("rice");
            AddUncountable("money");
            AddUncountable("species");
            AddUncountable("series");
            AddUncountable("fish");
            AddUncountable("sheep");
            AddUncountable("deer");
            AddUncountable("aircraft");
        }

        #endregion

        private class Rule
        {
            private readonly Regex _regex;
            private readonly string _replacement;

            public Rule(string pattern, string replacement)
            {
                _regex = new Regex(pattern, RegexOptions.IgnoreCase);
                _replacement = replacement;
            }

            public string Apply(string word)
            {
                if (!_regex.IsMatch(word))
                {
                    return null;
                }

                return _regex.Replace(word, _replacement);
            }
        }

        private static void AddIrregular(string singular, string plural)
        {
            AddPlural("(" + singular[0] + ")" + singular.Substring(1) + "$", "$1" + plural.Substring(1));
            AddSingular("(" + plural[0] + ")" + plural.Substring(1) + "$", "$1" + singular.Substring(1));
        }

        private static void AddUncountable(string word)
        {
            _uncountables.Add(word.ToLower());
        }

        private static void AddPlural(string rule, string replacement)
        {
            _plurals.Add(new Rule(rule, replacement));
        }

        private static void AddSingular(string rule, string replacement)
        {
            _singulars.Add(new Rule(rule, replacement));
        }

        private static readonly List<Rule> _plurals = new List<Rule>();
        private static readonly List<Rule> _singulars = new List<Rule>();
        private static readonly List<string> _uncountables = new List<string>();

        public static string Pluralize(this string word)
        {
            return ApplyRules(_plurals, word);
        }

        public static string Singularize(this string word)
        {
            return ApplyRules(_singulars, word);
        }

        private static string ApplyRules(List<Rule> rules, string word)
        {
            string result = word;

            if (!_uncountables.Contains(word.ToLower()))
            {
                for (int i = rules.Count - 1; i >= 0; i--)
                {
                    if ((result = rules[i].Apply(word)) != null)
                    {
                        break;
                    }
                }
            }

            return result;
        }

        public static string Titleize(this string word)
        {
            return Regex.Replace(Humanize(Underscore(word)), @"\b([a-z])",
                                 delegate(Match match)
                                 {
                                     return match.Captures[0].Value.ToUpper();
                                 });
        }

        public static string Humanize(this string lowercaseAndUnderscoredWord)
        {
            return Capitalize(Regex.Replace(lowercaseAndUnderscoredWord, @"_", " "));
        }

        public static string Pascalize(this string lowercaseAndUnderscoredWord)
        {
            return Regex.Replace(lowercaseAndUnderscoredWord, "(?:^|_)(.)",
                                 delegate(Match match)
                                 {
                                     return match.Groups[1].Value.ToUpper();
                                 });
        }

        public static string Camelize(this string lowercaseAndUnderscoredWord)
        {
            return Uncapitalize(Pascalize(lowercaseAndUnderscoredWord));
        }

        public static string Underscore(this string pascalCasedWord)
        {
            return Regex.Replace(
                Regex.Replace(
                    Regex.Replace(pascalCasedWord, @"([A-Z]+)([A-Z][a-z])", "$1_$2"), @"([a-z\d])([A-Z])",
                    "$1_$2"), @"[-\s]", "_").ToLower();
        }

        public static string Capitalize(this string word)
        {
            return word.Substring(0, 1).ToUpper() + word.Substring(1).ToLower();
        }

        public static string Uncapitalize(this string word)
        {
            return word.Substring(0, 1).ToLower() + word.Substring(1);
        }

        public static string Ordinalize(this string numberString)
        {
            return Ordanize(int.Parse(numberString), numberString);
        }

        public static string Ordinalize(this int number)
        {
            return Ordanize(number, number.ToString());
        }

        private static string Ordanize(int number, string numberString)
        {
            int nMod100 = number % 100;

            if (nMod100 >= 11 && nMod100 <= 13)
            {
                return numberString + "th";
            }

            switch (number % 10)
            {
                case 1:
                    return numberString + "st";
                case 2:
                    return numberString + "nd";
                case 3:
                    return numberString + "rd";
                default:
                    return numberString + "th";
            }
        }


        public static string Dasherize(this string underscoredWord)
        {
            return underscoredWord.Replace('_', '-');
        }
    }
}
